Posts Tagged ‘Acrylic’

We found a great little video on YouTube by user “Make:” which in just three minutes (before credits) gives all sorts of great tips for the DIYer using acrylic in their applications. It starts off with a good point that not everyone knows: acrylic comes in both cast and extruded forms. Yes, they have differences that are important in an application. Yes, there is a difference in cost. Other important tips include how to thermoform, glue, and most importantly – drill, the plastic. Drilling is especially important as the plastic can crack easily, so using lubrication and a soft touch is essential to prevent a wasted part. It will help you answer some questions you didn’t even know to ask prior to diving in: do you have all the materials you need? How are you planning to smooth the edges of the acrylic?

We’ll let the video do the rest of the talking:

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First things first, we here at Redwood Plastics (the administrators of the Plastichowto blog) are happy to answer your application related questions. That said, we might be able to save some time with your future DIY projects by helping you narrow down what plastics you might need for your application. If you’re still hesitant or have additional questions just ask us. Without further adieu, a list of plastics and where they might fit in to various applications:

UHMW polyethylene:

An incredibly versatile plastic, UHMWPE is the “Swiss army knife” of plastics. It’s good at a lot of things, great at a few things and substandard for a few applications. If you need an impact-zone UHMW works as it’s virtually unbreakable and it also works as synthetic ice (though unlike HDPE, it will dull skate blades). It functions well as light-load bushings (under 500 PSI) but cannot hold tight tolerances (+-) 0.05″ is about the best you’re reasonably going to get. We’ve seen UHMW used as sheaths for bladed objects and cutting boards as well. UHMW has benefits of being inexpensive compared to other industrial grade plastics and is also widely stocked.

Nylon:

Nylon’s main application in DIY applications is as sheaves and bushings. Nylon machines well and can handle 4000PSI in operation, which is why it works so well under load. You do need to be aware if your application is exposed to the sun (and therefore need UV-stabilizer) and if your application is marine. For “wet” applications acetal is recommended as a substitute because nylon will swell. In addition, nylon gets brittle below -10 degrees C.

Acetal:

An excellent all-around plastic, acetal can be substituted for nylon in most applications as it handles a similar load for applications like bushings and sheaves. In addition, acetal is the best engineering plastic to machine. It holds tight tolerances and is excellent for small, complex parts. A popular DIY application for acetal is replacing metal parts in paintball guns.

Tuffkast:

A premium nylon-like material, Tuffkast was designed to overcome the drawbacks of nylon. Tuffkast is better in the cold and absorbs much less moisture than nylon. It can be substituted in most applications the only potential issue is that it is softer than nylon, which may mean reduced wear properties in some applications. Otherwise, it is extremely versatile and would delight most DIY’ers if they only knew it better.

Acrylic/Polycarbonate:

Acrylic and polycarbonate are used where you need a clear plastic. Acrylic is not as strong as polycarbonate but it has better scratch resistance. Both plastics are much stronger than glass. In addition, acrylic resin is naturally UV-stabilized where only special grades for polycarbonate are. Safety glass, windows, canopies and tabletops are DIY applications for these plastics.

Phenolic/Industrial Laminates:

Industrial laminates are a very large family of plastics where different resin systems, substrates, and additives mean there isn’t a “one size fits all” phenolic. For the DIY community phenolics are fairly expensive and difficult to work with as you require dust exhausting systems and masks. Some are glass-filled which means special tooling to work with them. Phenolics can handle a large amount of load, often in excess of 20,000PSI and are primarily used in mechanical applications by the DIY community. So anywhere the plastic’s job is to provide strength, rigidity and form. It’s hard to narrow down specific applications for this – we’ve seen almost everything! But what comes to mind is, for example, replacing the metal collars on a sailboat (which hold the sail masts firm and steady) with phenolic. Remember, unlike metal, phenolics won’t corrode due to salt and water.

There are several other plastics we could talk about but their use by the DIY community would be limited. If you’re interested in discussing your application feel free to contact us.

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Acrylic sheet (sometimes called “acrylic glass”) is a well known plastic with countless applications for the “DIY” community. Everything from cold frames, to decorations, window replacements or even laser-etched business cards (look them up!). Acrylic offers several advantages other plastics, particularly see-through plastics, do not have. Acrylic’s main competitor in the world of plastics is Polycarbonate. Polycarbonate has higher impact strength than acrylic and should be selected when that is the main concern. Otherwise, acrylic will be slightly (about 15%) less expensive, have superior UV and weathering resistance and be much more scratch resistant: which is a major concern with polycarbonate.

Recently we stumbled across a website called www.instructables.com which has an index for all sorts of really neat acrylic projects to get your creative juices flowing! You can find these projects here: http://www.instructables.com/id/Projects-with-Acrylic/

instructables

Perhaps no industrial plastic is more requested by the “do-it-yourselfer” community than acrylic. Prized for its beauty and well-known because it is used in many applications where the public would encounter the material (displays, aquariums, giftware). In short, acrylic has gained an impressive reputation. But when you work with the material, especially if you’re inexperienced, you really need to do your due diligence in learning the strengths and weaknesses of acrylic and learn how to fabricate it properly.

One of the first tips – especially if you’re just starting out – is to temper your expectations. People imagine they can create polished, flawless projects at home similar to what they have seen in existing products or on the internet. But acrylic is “fussy” to fabricate, it can crack easily if fabrication is done near the edges of the material, it can scratch and the nice, polished finish you see is done by a technique called “flame-polishing” which is a skill that needs to be developed and requires special equipment.

We will provide a couple key tips on this blog but also want to direct you to another blog that seems to be an excellent resource for general acrylic fabrication, which can be found here.

Some tips we can offer:

-ALWAYS leave the masking cover on the acrylic (this provides protection from cracking).

-Avoid fabrication such as drilling near the edges of the acrylic (best to leave a couple inches) as the material can be prone to cracking.

-Acrylic has good UV-resistance, use it outdoors in confidence.

-Cure time for glued acrylic is around 48 hours – be sure you have a way of stabilizing your project while the glue bonds.

Lastly, for some quick tips on gluing acrylic check out this Youtube video:

 

So…You have a project. You’ve decided that you’re going to use “plastic” for it. Ok, which kind?

Sometimes it’s obvious. Plastic “do-it-yourselfer” applications that involve piping probably involve PVC since it’s so readily available and inexpensive compared to the alternatives. Same goes for acrylic or polycarbonate – the two primary clear (glazing) plastics. But sometimes there are more choices especially as the application becomes more vague. Common plastic applications taken on by amateurs include wear strips, bumpers, sheaves, pulleys, wheels, shock absorbers, ramps, bushings and everything else you can think of. With the array of industrial plastics available these days – how do you select the right plastic?

Well, the easiest way is just to ask. A reputable distributor will be able to take your information and make a recommendation; however, the more information you bring to the representative – the more he or she can help you. Many of the questions you ask should be the same as any of our industrial customers would ask. And we can help you out right here!

Questions you should know the answer to before approaching the plastic distributor:

What is the project?

What is the operating environment? (temperature, any chemical or weather exposure – exposure to UV light is of special concern)

What load or pressure does it bear?

What properties are important in your application? (stiffness, ease of machining, low friction, high friction, etc)

What is your budget?

Based on that information we can help you select a material that will suit your project’s needs.

For more information contact Redwood Plastics.

 

 

 

 

As summer comes to a close so does an experiment we ran at our Vancouver branch. While we try to minimize our offcuts, so as to reduce the amount of wasted material we create, we are still left with little bits here and there. Throughout the years our Marketing department, who handle our online inquiries, has noticed a number of customers asking about small pieces – which are apparently very difficult to find. We had the idea of taking stock of some offcuts and seeing if anyone would be interested in some small bits…Turns out they were!

Some projects we had come across our desks:

-PTFE base for a home telescope

-Phenolic saw guides

-“Wheel-less” dynamic surface for a sliding wardrobe door

-Acrylic table surfaces (quite a few of these)

-Polycarbonate for boat hatches

What did we learn? A lot. It was a great learning experience for ourselves and the customers. On the positive side we learned how creative the public can be with industrial plastics, particularly with the telescope and wardrobe that used UHMW strips as an ultra-low friction sliding surface. Also, it was interesting on how large of size “offcuts” were requested of us – often approaching 3/4 of a full sheet. Certainly there was no shortage of desire for industrial plastics and for so many different applications. It was refreshing to work on something new.

Unfortunately, those larger offcuts seemed to come in at prices that disappointed some customers, despite special pricing. Industrial plastics are an excellent material but they are not cheap like everyday consumer plastics. The larger offcut sizes in particular meant some disappointed customers could only be quoted on full sheet for their application at the regular price.

However, overall it was an interesting experiment and one we’ll continue to run as we gather more information on how to increase the footprint of industrial plastics.

Recently, Redwood Plastics started a pilot project marketing offcuts on local sales directories. This has greatly increased our inquiry traffic from the “diy” community and has been an eye-opener as far as what the general public would like to do with plastic in home applications. The ingenuity of the public is still fascinating and continues to surprise us.

One issue our customers are having is a lack of knowledge about whether they should select polycarbonate or acrylic for a given application. Indeed, the two materials are very different – almost mirror images as far as properties, advantages and drawbacks go. To help we’ve created a simple comparison chart for you. Feel free to copy and save it on your computer for your own reference.

A “takeaway” point from this article we hope you will understand is that acrylic and polycarbonate have certain advantages and disadvantages. There is no “magic bullet” or material that is absolutely superior to the other. You will need to prioritize what is most important for your application and make a selection based on your own criteria. We hope it is helpful!

Acrylic vs. Polycarbonate